The number of cancer patients who feel discriminated against when they return to work is increasing, according to a charity.

A survey conducted for Macmillan Cancer Support by YouGov found 37% who go back to their job after treatment say they experience some kind of discrimination from their employer or colleagues - compared to 23% in 2010.

When Hilary Norsworthy was diagnosed with breast cancer in November 2003 she had a full-time management job at a school in Kent.

After 11 months of treatment, she returned to work, but tells Sky News she was made to feel so unwelcome that she left after a month.

"I couldn't get into any of the computers at all," she said. "So when I asked the head teacher why not, he said 'because I've asked for your permissions to be removed'.

"I asked 'why' because I was in charge of the whole finances and just wanted to see what had been happening."

Hilary has worked out her pension pot is £2,000 a year smaller as a result of her leaving, because she resigned before retirement age.

She wishes she had felt strong enough to carry on.

"I was a good 100% within a year, but I needed to build up my confidence, and what they did was just knock me back down to the bottom.

Ms Norsworthy had treatment for breast cancer

"I felt as though the bottom had dropped out of my world, because that school was my world."

The survey of 168 cancer sufferers found 9% felt so harassed by their employer they felt they could not stay in their job.

Some 13% say their employer failed to make reasonable changes to enable them to do their work.

"People see cancer as something you either die from or survive and actually there's a growing number of people who complete treatments successfully but are having to deal for months, sometimes years, with the long-term consequences," he said.

The Equality Act 2010 was supposed to increase the rights of workers living with cancer.

Employment lawyer Merrill April says bosses have a legal responsibility to protect them from unfair treatment at work, including making reasonable changes to their work environment or hours.

"What will be reasonable depends on the size of the employer," he said.

"If they only employ three people and they've got no ability to cover for one person doing less work, then that is going to be harder for them to make adjustments."